[RFC PATCH] [XFRM] xfrm_algo: correct usage of RIPEMD-160

This patch makes HMAC-RIPEMD-160 usable with IPsec/XFRM. The RIPEMD-160
implementation is currently in the cryptodev-2.6 tree.

Since I have no IPsec test setup the patch has not (yet) been tested with
IPsec and is thus marked as RFC. I will put together a test environment which
will take some time. In the meantime it would be great if somebody who already
has a working IPsec environment could test this patch.

Thanks,
Adrian